This invention relates to a recording medium, playback apparatus and recording/playback apparatus thereof and more particularly to a recordable/playable recording medium such as a DVD-RAM and a recording/ playback apparatus which can be applied to a recording/ playback DVD player for recording or playing back an image and voice by use of the recording medium.
A playback-only optical disk having an image and voice recorded thereon is already put into practice as a music CD, laser disk, video CD or the like. MPEG2 (Moving Picture Experts Group Phase 2) which is the international standard specification for compression of moving pictures and a DVD specification using the AC3 audio compression system are defined and it is put into practice as a DVD video. The DVD specification is initially designed by taking a playback-only disk or a ROM disk which cannot be recorded by the user into consideration, but recently, a DVD-RAM specification which can be played back and recorded by the user was made.
At present, the DVD-RAM specification is realized in a data recording/playback apparatus for a computer, but as a matter of course, application to a DVD recording/playback apparatus for recording/playback a moving picture and voice is studied. When application of the DVD-RAM specification to the DVD recording/playback apparatus is considered, it is desirable to effect the searching operation in the same manner as in the specification for DVD audio and DVD video based on the DVD specification for playback only.
In the DVD video specification, VMG.VTS menus are provided for disk title creating companies. The menus are created by use of an exclusive authoring instrument. Then, the recording content of the disk is displayed in the form of menu in addition to normal video data at the time of playback and buttons are displayed by use of a sub-video image so as to permit the user to select them, thereby making it possible to search for a desired portion.
On the other hand, when a moving picture is recorded by use of the DVD-RAM, the user creates a title, and if VMG.VTS menu data used in the DVD video specification is used, the user also crates them. However, it is extremely difficult for the ordinary user to create the VMG.VTS menu data when considering the large amount of data and devices which must be prepared to create the menu data and it is not practical. Further, in the case of recordable/playable DVD, the operation for re-recording main record data (video, voice data) is frequently effected, but if the VMG.VTS menu data is used, the VMG.VTS menu data must be rewritten each time the main record data is rewritten and the amount of operations for this purpose becomes extremely large.
As described above, when a moving picture and voice are recorded by use of the DVD-RAM, use of VMG.VTS menu data used in the DVD video specification in which the main record data is not assumed to be rewritten imposes an extremely heavy load on the user and it is not practical.
This invention has been made to solve the above problem and an object of this invention is to provided a recordable/playable recording medium and recording/playback apparatus capable of easily effecting the searching and editing operations without making it necessary to create troublesome menu data.
A recording/playback apparatus according to this invention is a recording/playback apparatus for recording or playing back main record data containing information of at least one of an image and voice and comprises trigger supplying means for supplying a trigger for registering an index image; position information acquiring means for acquiring recording position information on the recording medium of an image which is now being recorded in response to a trigger supplied by the trigger supplying means: and position recording means for recording the recording position information acquired by the position information acquiring means on the recording medium at the time of termination of the image recording. As the recording position information, a sector number and cell number of an image which is now being recorded are contained.
Further, a recording/playback apparatus according to this invention comprises creating means for creating index image data in response to a trigger supplied from the trigger supplying means; and index image recording means for recording the recording position information acquired by the position information acquiring means and the index image data created by the creating means on the recording medium at the time of termination of the image recording.
Further, a recording/playback apparatus according to this invention comprises time information acquiring means for acquiring display time information of an image which is now being recorded in response to a trigger supplied from the trigger supplying means; and time information recording means for recording the display time information acquired by the time information acquiring means on the recording medium at the time of termination of the image recording. The recorded image is processed in the unit of program and the time information is the number of fields counted from the starting time of the program which is now to be defined.
Further, a recordable/playable recording medium according to this invention comprises an area for recording record position information of an image in the main record data; and an index image recording area for recording image data of the selected image in the main record data as an index image.
According to this invention, recording position information of an image selected in the main record data is recorded on the recording medium and image data of the image selected in the main record data is alternatively or additionally recorded as an index image. By using information of an image and voice recorded in a recording position indicated by the position information or the index image (compressed or reduced image data) as a menu at the time of playback, the user can immediately detect the recording information on the recording medium.
Therefore, it becomes possible for the user to quickly search for a desired portion based on the menu or efficiently effect the editing operation such as erase or replacement of information of a desired area on the recording medium.